Da Nang police have seized a luxury Bentley car with a fake license plate, saying the vehicle that is worth around US$268,000 might have been smuggled into Vietnam.
Police checked the car when it was parked on a street in the city on October 13.
The driver, Hoang Dung Man of Quang Binh Province, was unable to produce any documents proving legal origin of the car, he said.
Police said the license number on the car actually belonged to another car registered in Hanoi.
They are investigating the case.
Vietnam has emerged as a growing market for luxury cars in recent years.
Due to high taxes and fees that can cause car prices to double, some people have bought cars from diplomats, who enjoy tax exemption, without registering new ownership.
The Ministry of Finance in 2013 said it had found at least 1,200 of such purchases.
Since 2013, relevant agencies have stepped up inspections of these cars, which carry license plates marked with the letters NG or NN for "foreign affairs" or "foreigners" in Vietnamese.
The government recently submitted to the National Assembly a plan to increase luxury taxes on expensive cars with large engines. The tax rate could increase to 150 percent from the current 50-60 percent.
Under the proposal, the price of a Rolls-Royce Phantom in Vietnam, for instance, can rise from the current VND30 billion ($1.34 million) to nearly VND47 billion ($2.1 million), local media reported.